The father of a teenager encouraged to marry and rape his 12-year-old cousin was jailed for three years today.

The 54-year-old man was arrested by Scotland Yard child abuse detectives over an arranged marriage at a house in Woolwich, south east London.

Investigators discovered a 16-year-old boy was told by several family members to illegally marry the young relative and have sex with her.

The sham Muslim ceremony took place at his parents' house in front of relatives in March last year.

The victim's mother alerted police and the teenage boy, his parents and the girl's 29-year-old father were arrested and questioned.

The Metropolitan Police said the boy, now aged 17, was sentenced to an 18-month supervision order at Wood Green Crown Court today.

He was also ordered to sign the sex offenders' register after a jury found him guilty of raping a girl aged under 13.

His parents, both aged 54, and the girl's father were convicted of inciting a child under 13 to engage in sexual activity following an illegal marriage.

The teenage boy's mother received a 12-month jail term, suspended for two years, and was ordered to undertake 200 hours' community service.

The 12-year-old victim's father was jailed for three years and will be placed on the sex offenders' register for life.

In a statement, the victim's mother said: "What happened to my daughter was a nightmare. These convictions will help us move on."

Detective Inspector Noel McHugh, who led the investigation, said the sentences should bring closure to a "really awful crime".

He said: "This has been an exceptionally challenging investigation and we are grateful to all those who assisted with the case and ensured the convictions.

"The offences committed are incomprehensible and the victim is a truly brave girl who suffered at the hands of those who should have offered her protection. The girl and her mother assisted the investigation throughout."